As used herein the term “digestive trace” includes, but is not limited to, the mouth, pharynx, esophagus, stomach, small intestine and large intestine. Also, as used herein, the terms “colonic residue” and “residue” include any composition of matter resulting from digested food and other body waste which has not been absorbed by the body's digestive system. Such residue includes, but is not limited to, any solid, semi-solid or liquid stool matter.
Removal of stool matter from the digestive tract has historically been necessary to effectively screen for gastrointestinal abnormalities, including, but not limited to, cancer such as colon cancer. Since colon cancer is a highly treatable and often curable if detected early, screening tests for detecting premalignant polyps and colorectal cancers at stages early enough for complete removal are very important.
Colon screening procedures include, for example, barium enema, sigmoidoscopy and fiberoptic colonoscopy. The most recent technological advancement in colon screening is virtual colonoscopy/CT Colonography. This procedure utilizes computer reformation of radiologic images to form images of the colon in two or three dimensions. Historically, sufficient amounts of stool matter had to be removed from the colon prior to a virtual colonoscopy procedure. This is because stool and colon lesions are not easily distinguishable in computer tomography or other radiologic modality images, thus preventing physician's ability to distinguish pathology from retained fecal debris. In one alternative embodiment, the present invention is a method for marking colonic residue (e.g., stool) present in an individual's digestive tract (e.g., colon) with a radiopaque material before the digestive tract is imaged. The marked stool, for example, can then be readily identified in the images. Alternatively, the marked stool can be identified and/or electronically removed from the images.
U.S. Pat. No. 6,477,401 to Johnson et. al. is directed to a method of generating colonography images of a patient's unprepared colon for colorectal screening. This method requires providing the patient at least 10 grams of stool marker in doses over at least a 48 hour administration period.
The present invention is distinguishable, and is more advantageous over the methods disclosed in the '401 patent. For example, in one alternative embodiment of the present invention, the individual's stool is sufficiently marked within 24 hours. This improves the patient's compliance to the tagging and/or dietary regimen prior to the predetermined activity. Also, in contrast to the '401 patent, in one alternative embodiment, the present invention limits the amount of tagging doses to 3 or less over a 24-hour administration period. This is accomplished by providing small volumes of liquid containing high concentrations of tagging agent. Further, the present invention minimizes the amount of stool retained in the gastrointestinal tract (e.g., colon) by administering a low residue diet to the individual prior to the predetermined activity. This provides several advantages. For example, in some situations, the physician may require the individual to undergo a laxative prior to the predetermined procedure. Because the present invention minimizes the production of stool, the patient need only take a mild laxative, as opposed to a cathartic. Also, because low amounts of stool are present, there is no need to utilize special software to remove the marked stool from the images of the individual's tissue, for example. All considered, the present invention, in contrast to the '401 patent, provides a cleaner gastrointestinal tract (e.g., colon) with less fluid and less retained stool. Other advantages of the present invention are described herein.
There is, therefore, a need for a colonic residue tagging regimen which effectively marks colonic residue in the digestive tract while providing the user with a sufficient level of calories and nutrition to conduct routine, daily activities. Additionally, there is a need for a tagging regimen which is readily useable and convenient, which also minimizes the amount of fluid or stool formation prior to the predetermined activity. In addition, there is a need for a dietary regimen to be used in conjunction with a tagging regimen, while at the same time facilitating user compliance since current tagging regimens are difficult or painful to complete. The consequences of non-compliance can be great. For example, noncompliance can result in an ineffective colon screening.